Sulfonamide anticonvulsant
Blocks voltage-gated sodium and T-type calcium channels, stabilizing neuronal membranes and reducing excitability
Adjunctive treatment of partial-onset seizures in adults with epilepsy
Augmentation in bipolar disorder, migraine prophylaxis, weight loss in obesity, management of impulsivity and aggression in traumatic brain injury (TBI) or neurodevelopmental disorders
Oral capsules and tablets
Start at 50 mg p.o. daily, titrated gradually by 50–100 mg every 1–2 weeks based on response and tolerability
100–400 mg/day, usually once or twice daily
Half-life approximately 63 hours; metabolized hepatically (CYP3A4) and renally excreted; low protein binding
Fatigue, dizziness, nausea, anorexia, cognitive slowing, agitation
Kidney stones, metabolic acidosis, oligohidrosis, Stevens-Johnson syndrome
Periodic monitoring of electrolytes, renal function, and serum bicarbonate levels
None
Zonisamide may benefit patients with comorbid obesity, mood instability, or impulsivity related to TBI or neurodevelopmental disorders. Use caution in individuals with cognitive impairment, as word-finding difficulty and psychomotor slowing may occur. Avoid use in patients with sulfa allergy.